Perimeter warning systems are allowed by law in many jurisdictions, including throughout the United States, as a substitute for harnesses and other protective equipment, to provide workers with a warning that they are approaching the edge of a safe zone, such as an open floor of a building under construction. Such warning lines can be substituted for fall-prevention equipment under certain circumstances. They are considered, as well, a genuine aid to persons at risk, even in locations where such safety protection is not mandated.
According to the Occupational Safety and Health Administration (OSHA) of the United States, along with mandated safety requirements for workers at height, additional fall protection systems can be used. Among these are warning lines systems, pursuant to 29 CFR 1926.502(f).
OSHA defines a warning line system as a barrier erected on a roof to warn workers that they are approaching an unprotected roof side or edge, and to designate an area in which roofing work may take place without the use of guardrails, body harnesses, or safety net systems to protect workers in the area. Warning line systems consist of ropes, wires, or chains, plus supporting stanchions. If an employer chooses to use warning line systems, the following provisions apply:                The warning line must be erected around all sides of roof work areas. 29 CFR 1926.502(f)(1).        When mechanical equipment is not being used, the warning line must be erected at least 6 feet from the roof edge. 29 CFR 1926.502(f)(1)(i).        When mechanical equipment is being used the warning line must be erected:                    At least 6 feet from the roof edge parallel to the direction of mechanical equipment operation; and            At least 10 feet from the roof edge perpendicular to the direction of mechanical equipment operation. 29 CFR 1926.502(f)(1)(ii).                        The rope, wire, or chain must be flagged at not more than 6-foot intervals with high-visibility material. 29 CFR 1926.502(f)(2)(i).        The rope, wire, or chain must be rigged and supported so that:                    The lowest point (including sag) is at least 34 inches from the walking or working surface; and            Its highest point is no more than 39 inches from the walking or working surface. 29 CFR 1926.502(f)(2)(ii).                        Stanchions, after being rigged with warning lines, must be capable of resisting, without tipping over, a force of at least 16 pounds applied horizontally against the stanchion, 30 inches above the walking or working surface, perpendicular to the warning line and in the direction of the floor, roof, or platform edge. 29 CFR 1926.502(f)(2)(iii).        The rope, wire, or chain must have a minimum tensile strength of 500 pounds. After being attached to the stanchions, it must support, without breaking, the loads applied to the stanchions as prescribed in 29 CFR 1926.502(f)(2)(iii) & 29 CFR 1926.502(f)(2)(iv).        The rope, wire, or chain must be attached to each stanchion in such a way that pulling on one section of the line between stanchions will not result in slack being taken up in the adjacent section before the stanchion tips over. 29 CFR 1926.502(f)(2)(v).        
These regulations are well known and followed throughout the United States, as well as in other countries where US guidelines are adopted as helpful. There are any number of perimeter warning systems available in the marketplace. However, problems subsist in that existing warning schemes that comprise perimeter lines require, by regulation, additional elements to keep the lines in place and provide a substantial visual indication as to where the perimeter is. While most of these systems comprise a length of cord or string, wire cable to mark the perimeter and many of those include pennants or flags at regular intervals to allow the perimeter to be seen at a distance or in conditions where visibility is affected, all of such systems are subject to exterior elements such as wind, weather and other conditions that can inflict damage to such components as the flags and ropes/wires/cables used. As noted above, the regulations allow work to continue while the warning system is in place and would require that work stop if any of the above noted regulations was not extant and not start again until equipment, to the letter of the regulations, is restored. It will be seen that such warning systems are an accommodation to work and construction zones, but if not properly done and maintained, would force work to stop until properly done or replaced by more stringent harness and protective equipment standards.
Additionally, problems in the prior usage of warning lines include: where the flags and lines are attached to poles, columns or other upright members, places to mount the upright members in a structure under construction (where a perimeter warning is needed) can be problematic and require continued maintenance. Where apparatus to mount the flag lines has been created, problems exist with storing and moving such devices as construction progresses or to new locations or moving them into storage for future use. Existing devices have been found to be difficult to use, maintain in place, store, transport and reuse, due to such things as the large variety of roofs and roof types, building floors, sizes and areas and roofing materials; bulky items used to string perimeter lines are often required to provide the weight and mass to anchor the warning line as required by law; movement of a warning line system from storage to situs of use and/or their return to storage is difficult, due generally to the weight and bulkiness of the warning systems in general and the effort needed to neatly collect and store such systems. Where such systems lack bulk they typically have been found to fail in adverse condition, increasing the danger to workers or the stoppage of work until the perimeter lines can be restored.
It would be desirable to have a perimeter warning system that is easy to be seen and therefore provide a safe work environment as well as be easy to store and deploy, be capable of sustaining itself on a roof or open floor situation regardless of wind and weather situations and can be easily collected and stored and then transported quickly and efficiently as needed, while maintaining the integrity of the components for use and reuse.
It is therefore an object of the present invention to provide a means for having a safe, effective, storable and transportable warning system for workers working at height and at other perimeter situations. Other objects and advantages of the present invention will become apparent as the description proceeds.